In the past, microphones have been adjustably mounted for proper positioning of the microphone in relation to the mouth of the speaker in radio studios, lecture halls and the like. With the advent of telephones and citizen band radios in motor vehicles, microphones have been inserted in a well or cavity in the top end of a steering column or the microphone was attached to flexible extension wires for manual handling.
Motor vehicles present special problems in the use of microphones. For example, motor vehicles create wheel noise. Traffic creates nuisance noise. These noises readily enter the microphone if not overcome. The driver of a motor vehicle must keep both hands on the steering wheel to safely drive the vehicle. One hand cannot be used to hold a microphone in traffic or at high speeds or when shifting gears. The microphone is normally closed to shut out noise and must be activated to become effective.